This invention relates to a thick film printing method by an intaglio offset printing device which uses a transferring body.
An important field in the electronics industry is the formation of fine conductive film patterns or fine resistance film patterns on substrates or electrode plates used in various electrical devices such as pringing circuits, liquid crystal display panels, plasma display panels and so on. These patterned conductive films or resistance films are advantageous in that the pattern density can be raised as the line width is made smaller. For example, photoetching is one of the most popular techniques for forming fine film patterns. In this method, a film of uniform thickness is formed on a substrate by means such as vacuum deposition, and the film is patterned using a photoresist and chemical corrosion. As such, this method requires many steps, and equipment and raw materials therefor are expensive. Since the photoetching method is costly, the application of this method tends to be limited to products of higher cost. Products are generally expensive if the line width of the fine patterns is 2-30 .mu.(microns). The photoetching method is thus generally used to manufacture such products.
Among other conventional printing methods is the screen printing method wherein the thickness of the printed ink film can be made great. This method is advantageous in that discontinuities and thin sections are rare so that stable electric performance of the conductive film or resistance films can be obtained. However, since a screen mesh of stainless steel or nylon is made to cover a plate, deformation due to squeeze pressure is generated, and errors in dimensional accuracy or positioning accuracy tend to occur after a number of printings. Further, since ink reaches the material to be printed through the intermediary of the screen mesh, the shape of the boundary of the ink image is often irregular. In addition, it is difficult to print fine patterns with stability, for example, fine patterns of 100 .mu. or less line width. The printing pattern, depending on its shape, generates a moire phenomenon with the screen mesh, and a moire pattern on the printed material.
Thus, there has not been proposed in the prior art an appropriate method for printing an intermediate pattern whose line width is 30-300 .mu..